The FlightGear developers generally release a stable packaged version of FlightGear, with an easy install wizard, about once or twice a year. For convenience, most FlightGear users download and install these packages.

However, the source files used to build the whole FlightGear package are continuously being developed by dozens of contributors, who collaborate using the source code management system Git to create a new "unstable" version every few days. If you want to use one of these unstable versions, or tinker with the source files to create your own custom version, the pages below describe how to compile the FlightGear package from the Git source files (repository at Gitorious.org).

If you'd like to use an integrated development environment, illustrated instructions for building FlightGear and its dependencies can be found in Howto:Build FlightGear with NetBeans using CMake, this should work on both, Windows and Linux systems (NetBeans being a cross-platform IDE).

Another option to run the latest code without having to compile everything yourself, is using a precompiled binary provided by the FlightGear Build Server which is based on Jenkins.